One proposed power output apparatus mounted on a motor vehicle has two structure configurations, in each of which an engine is connected to a rotating shaft of a motor via a clutch. In this prior art power output apparatus, an actuator unit is attached to a transmission linked with an axle of the motor vehicle, and the two structure configurations are connected to the actuator unit via respective clutches and brakes (see, for example, Japanese Patent Laid-Open Gazette No. H11-311137). Appropriate coupling and release of the clutches and the brakes and the operations of the engines at efficient drive points in various combinations of the two motors and two engines are expected to increase the overall energy efficiency of the whole motor vehicle.